Kelp gulls attack Southern right whales: a conservation concern?

Abstract

Kelp gulls (Larus dominicanus) feed on pieces of skin and blubber they rip from Southern right whales’ (Eubalaena australis) backs in their breeding areas at Península Valdés, Argentina, producing injuries. This behavior has increased since the first record in 1972, and some authors have suggested that constant gull harassment could have a negative effect on right whale population. The main goal of this study is to assess the variables that most affect the gull attacks. We analyzed 5359 whale-watching sightings made during trips from Puerto Pirámides (42º34′S, 64º16′W) along the whale breeding seasons (June–December) 2005 to 2007. The most important factors affecting the attacks include the presence of a mother–calf pair, the time within the season, the distance to the coast and the wind velocity. There is also concern of possible transmission of infectious diseases in the attacks since increasing number of whales with different patterns of skin lesions have been observed.